Randerson stood for the leadership of the Welsh Liberal Democrats in 2008 but was defeated by Kirsty Williams who gained 60% to Jenny's 40% of the all member ballot. In the third Assembly Jenny Randerson was the Liberal Democrat spokesperson on Education, Transport and the Economy. She did not seek re-election at the 2011 Assembly elections, with Nigel Howells - her Liberal Democrat successor, being narrowly defeated by Jenny Rathbone.[]

Baroness Randerson is the first female Welsh Liberal Democrat to hold ministerial office at Westminster and the first Welsh Liberal to hold a ministerial post since Gwilym Lloyd-George in 1945. Although English by birth and upbringing, she is also the first female non Labour Welsh politician to hold a government post at Westminster.[]